Minimally invasive procedures have been implemented in a variety of medical settings, e.g., for vascular interventions, such as angioplasty, stenting, embolic protection, electrical heart stimulation, heart mapping and visualization, delivery of pacemakers, and the like. These procedures generally rely on accurately navigating and placing instruments within a patient's vasculature.
During such procedures, a target vessel may be accessed using a guide wire advanced through the intervening vasculature into the target vessel, thereby providing a “railway” to the vessel. One or more instruments, e.g., catheters, sheaths, and the like, may be advanced over the guide wire or “rail” into a vessel, heart, artery, vein, and/or other body cavity or lumen.
In some cases, a sheath placed within a body cavity or lumen may then be used to deliver another device, such as a pacemaker lead, stent catheter, another sheath, and/or other device. Further, it may be desirable that such a delivery sheath exhibit certain properties, such as pushability, kink resistance, retention of shape, and/or durability in order to facilitate its own navigation into a body lumen or cavity and subsequent placement of a lead or device through it. Yet further, it may be desirable to maintain the stability of placement of a lead or device positioned within a body cavity or lumen while removing a delivery sheath. Removal is often accomplished by peeling, cutting, or slitting.
However, techniques (such as braid reinforcement) used to impart characteristics of pushability, kink resistance, and the like, may decrease the ease with which a sheath may be removed. For example, a braid reinforced sheath must generally be cut away using a slitter or other cutting tool, rather than peeled away as a non braid reinforced sheath might be. Further, cutting through a braid may be difficult or inconsistent, increasing the likelihood of dislodgment of a lead or other device during removal of the delivery sheath.
Accordingly, it may be useful to provide a delivery sheath that is pushable, kink resistant, and the like and/or that may be easily removed from a body while leaving a remaining lead or other device in place without substantially disturbing its placement.